Circuitry component and method for forming the same

ABSTRACT

A circuit structure includes a semiconductor substrate, first and second metallic posts over the semiconductor substrate, an insulating layer over the semiconductor substrate and covering the first and second metallic posts, first and second bumps over the first and second metallic posts or over the insulating layer. The first and second metallic posts have a height of between 20 and 300 microns, with the ratio of the maximum horizontal dimension thereof to the height thereof being less than 4. The distance between the center of the first bump and the center of the second bump is between 10 and 250 microns.

INCORPORATION BY REFERENCE

The publications noted inthe disclosure herein are each fullyincorporated by reference, as if fully set forth in tis entirety herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to semiconductor devices, particularly tostructures of semiconductor devices, and more particularly to postpassivation structures for semiconductor devices and packaging processesfor such.

2. Description of Related Art

Semiconductor wafers are processed to produce IC (integrated circuit)chip having ever-increasing device density and shrinking featuregeometries. Multiple conductive and insulating layers are required toenable the interconnection and isolation of the large number ofsemiconductor devices in different layers (e.g., active and passivedevices, such as TFT, CMOS, capacitors, inductors, resistors, etc). Suchlarge scale integration results in increasing number of electricalconnections between various layers and semiconductor devices. It alsoleads to an increasing number of leads to the resultant IC chip. Theseleads are exposed through a passivation layer of the IC chip,terminating in I/O pads that allow connections to external contactstructures in a chip package.

Wafer-Level Packaging (WLP) refers to the technology of packaging an ICchip at wafer level, instead of the traditional process of assemblingthe package of each individual unit after wafer dicing. WLP allows forthe integration of wafer fabrication, packaging, test, and burn-in atthe wafer level, before being singulated by dicing for final assemblyinto a chip carrier package (e.g., a ball grid array (BGA) package). Theadvantages offered by WLP include smaller size (reduced footprint andthickness), lesser weight, relatively easier assembly process, loweroverall production costs, and improvement in electrical performance. WLPtherefore streamlines the manufacturing process undergone by a devicefrom silicon start to customer shipment. While WLP is a high throughputand low cost approach to IC chip packaging, it however invitessignificant challenges in manufacturability and structural reliability.

WLP basically consists of extending the wafer fabrication processes toinclude device interconnection and device passivation processes. Thefirst step to WLP is to enlarge the pad pitch of standard ICs byredistribution technology post passivation of the IC semiconductorstructure. Low cost stencil printing of solder or placing preformedsolder balls is then possible. Examples of redistribution technology aredisclosed, for example, in U.S. Pat. No. 6,642,136; U.S. Pat. No.6,784,087; and U.S. Pat. No. 6,818,545, commonly assigned to theassignee of the present invention. As disclosed in these patents, aredistribution layer (RDL) contacts the I/O pad of the semiconductorstructure. The RDL is supported on a layer of polymer or elastomerdeposited over a passivation layer. A contact post is formed on the RDL,using a photo-masking process. The resultant contact post isfreestanding, unsupported on its lateral sides. The resultant structurecan be further assembled into a chip carrier package using flip chipassembly technique. While the post passivation structures and relatedprocesses provide for IC packaging with improved pitch resolution, thereis still a limitation to meeting the increasing demand for finer pitchresolution in view of the ever increasing scale of integration in ICs.There is also potential risk for stress-induced failures, as notedbelow.

U.S. Pat. No. 6,103,552 discloses another WLP process including a postpassivation RDL. The RDL is supported on a layer of polymeric materialthat is deposited on the passivation layer of the semiconductorstructure. Another polymeric layer is deposited over the RDL, and etchedor drilled to provide a via for over-filling with a metal to form aninterconnect (i.e., a conducting post) that extends above and beyond theopening of the via. The top polymeric layer and the bottom polymericlayer are separated by a layer of chrome-copper, and therefore do nottouch between the RDL structures. A solder bump attached to theprotruding end of the post is formed by electroless plating, screen orstencil printing. Because the post extends beyond the surface of thepolymeric layer, and the top surface of the structure is otherwise notsmooth, high-resolution lithography cannot be achieved to form the viasfor the conductive posts and to plate the solder bumps. Consequently,the pitch of the contacts for the IC package would be limited. Thislimitation would be more pronounced with an increase in thickness of thepolymeric layer, which otherwise may be desirable to provide betterstress relief, as discussed below. Further, as noted, the bottompolymeric layer is separate from the top polymeric layer, therefore thebottom polymeric layer alone does not provide good stress relief. If thebottom polymeric layer is made thin to reduce lateral RDL displacements,stress relief would be poor, leading to issues further discussed below.

One of the challenges to structural reliability includes providingadequate stress relief in the resultant WLP processed multilayeredstructure, including the semiconductor IC die and the additional postpassivation structure. For example, the thin film bonded on thepassivation layer is subject to biaxial stress that is thermallyinduced. Equation (1) represents a theoretical mathematical modeling ofthe biaxial thermal stress in the post passivation thin film inrelationship to various physical parameters of the bonded structure on asilicon (Si) substrate:

$\begin{matrix}{\sigma_{ppt} = {\frac{1}{6R}\;\frac{Y_{s}\; x_{Si}^{2}}{\left( {1 - v_{Si}} \right)\; x_{ppt}}}} & {{Equation}\mspace{14mu}(1)}\end{matrix}$where:

σ_(ppt)=σ_(x)=σ_(y); biaxial stress in the post passivation thin film;

R=radius of curvature of the Si substrate caused by thermal stress;

Y_(S)=Young's modulus of Si substrate;

v_(si)=Poisson's ratio of Si substrate;

x_(Si)=thickness of Si substrate; and

x_(ppt)=thickness of the post-passivation thin film.

Based on the above formula, there are two ways to lowering the biaxialstress σ_(ppt) (in addition to increasing v_(si)): (a) lower x_(Si),which means making the Si substrate thinner; or (b) increase x_(ppt),which means increasing the thickness of the post-passivation thin filmstructure.

FIG. 1 schematically shows a prior art post passivation structure 10,including an RDL 12 and a stress-relieving polymer (or stress buffer)layer 14, formed over a passivation layer 16 at the top layer of thesemiconductor IC chip 18. The polymer layer 14 is made of, for example,an elastomer, epoxy, low-K dielectric material, or other polymer.Elastomer is used mainly for providing sufficient mechanical flexibilityfor the bonded structure. As can also be deduced from Equation (1)above, when a polymer layer is deposited over an IC chip 18, the stressgenerated by the chip and the structure bonded thereto can be absorbedor buffered to reduce local damage to the chip; this in turn enhancesthe reliability of the structure 10, especially the delicate circuits inthe IC chip. According to the relationship set forth in Equation (1),the performance of this buffering effect is increased as the thicknessof the polymer layer increases.

There is a generic problem associated with using a thick polymer layer.The RDL 12 shown in FIG. 1 is typically made of copper; it is intendedto connect IC I/O pads 20 on the IC chip 18 to external circuitry. Whendeposited with solder bumps and/or provided with copper conductive postatop at pads 22, the RDL 12 can be bonded to the next level packagingstructure firmly (e.g., a chip carrier). The RDL 12 escalates from alower plane (i.e., the plane with the IC I/O pads 20) to a higher one(the top of the polymer) via a sloping ramp 22 defined by the polymerlayer 14. The slope in the ramp 22 is desired for metal step coverage onthe sidewall of the thick opening in the polymer layer 14. In practice,the slope of the ramp 22 could vary for each opening in the polymerlayer 14, depending on the actual process conditions and inherentphysical properties and characteristics of the polymer (e.g., wettingangle, which has to do with the surface energy of the materials). Forexample, in many cases the slope of the ramp 22 in the polymer layer 14on the IC passivation layer 16 can be as low as about 45°. Consequently,the RDL 12 must necessarily translate by a significant amount of lateraldisplacement to extend from the IC I/O pad 20 to the top of the thicklayer of polymer 14. Consequently, this lateral displacementnecessitates the allowance of a significant amount of tolerance in thelayout of the RDL 12. As a result of the tolerance allowance necessaryto accommodate the varying slopes of ramps for different openings in thepolymer layer 14 and the varying lateral displacements of RDLs, thepitch between adjacent contact structures (e.g., defined by solder bumpsand/or copper posts) on the RDLs is limited, and the distances betweenthe contact structures and the openings in the passivation layer areincreased. This results in a post passivation structure that does nothave fine pitch structures for the next level of packing structure. Onthe other hand, if a thick layer of polymer is not used, stressbuffering would not be sufficient, leading to possible stress inducedfailure of the delicate circuits in the IC chip. Further, there would beinsufficient lateral support to tall conductive posts, resulting inlimited pitch of the I/O structures. It is desirable to have tallconductive posts, as they provide sufficient distance to reducecapacitance coupling between the I/O pads 22 and the electrical circuitsin the IC chip 18.

The issues noted above collectively placed a limitation on reducing thepitch of the contact structures achievable on the post passivationstructures, and thus also a limitation on increasing the scale ofintegration of ICs.

It is desirable to provide a WLP structure, and a process relating tosame, that allows for both improved stress relief and fine pitch contactstructures.

SUMMARY OF THE INVENTION

The present invention overcomes the drawbacks of the prior art, byproviding post passivation structures and related processes thataccommodate both stress relief and fine pitch contact structures. Inaccordance with the present invention, a pitch of <250 μm, and a pincount of >400 may be achieved for the IC packaging.

In one aspect, the present invention provides a post passivationrerouting support structure that comprises a relatively thin supportlayer (e.g., a polymer layer) above the passivation layer to supportfine pitch rerouting structures, and in addition a relatively thicksupport layer (e.g., a polymer layer) for the fine pitch reroutingstructures for next level packaging structure.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a substrate; a firstmetallic post, formed on the substrate, and 20 to 300 microns high withthe ratio of the maximum horizontal dimension thereof to the heightthereof less than 4; and a second metallic post, formed on thesubstrate, and 20 to 300 microns high with the ratio of the maximumhorizontal dimension thereof to the height thereof less than 4, whereinthe distance between the center of the first metallic post to the centerof the second metallic post is 10 to 250 microns.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a first metallic post, formed on the semiconductor substrate, and 20 to300 microns high with the ratio of the maximum horizontal dimensionthereof to the height thereof less than 4; a second metallic post,formed on the semiconductor substrate, and 20 to 300 microns high withthe ratio of the maximum horizontal dimension thereof to the heightthereof less than 4; an insulation layer, formed on the semiconductorsubstrate, and covering the first and second metallic posts; a firstbump, formed on the first metallic post or the insulation layer; and asecond bump, formed on the second post or the insulation layer, whereinthe distance between the center of the first bump and the center of thesecond bump is 10 to 250 microns.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a first metallic post, formed on the semiconductor substrate, and 20 to300 microns high with the ratio of the maximum horizontal dimensionthereof to the height thereof less than 4; a second metallic post,formed on the semiconductor substrate, and 20 to 300 microns high withthe ratio of the maximum horizontal dimension thereof to the heightthereof less than 4; and a metallic wire, interconnecting the top of thefirst metallic post and the top of the second metallic post, wherein thematerial of the metallic wire includes gold.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a first metallic post, formed on the semiconductor substrate, and 20 to300 microns high with the ratio of the maximum horizontal dimensionthereof to the height thereof less than 4; a second metallic post,formed on the semiconductor substrate, and 20 to 300 microns high withthe ratio of the maximum horizontal dimension thereof to the heightthereof less than 4; a metallic wire, interconnecting the top of thefirst metallic post and the top of the second metallic post; and apolymer layer, formed on the metallic circuit.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4, wherein a conductive wire can beconnected to the metallic post or the semiconductor substrate with awire-bonding method.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; and a polymer layer, formed on thesemiconductor substrate, and covering the metallic post, wherein a bump10˜150 microns high can be formed on the metallic post or the insulationlayer.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; a polymer layer, formed on thesemiconductor substrate, and covering the metallic post; and a metalliccoil, formed on the polymer layer, and 1 to 15 microns thick.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; and a bump, formed on the metallicpost or the semiconductor substrate, wherein the bump may be a 10 to 30microns thick golden layer.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; and a bump, formed on the metallicpost or the semiconductor substrate, wherein the bump may be atitanium-containing metallic layer.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; and a bump, formed on the metallicpost or the semiconductor substrate, wherein the bump may be achromium-containing metallic layer.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; and a bump, formed on the metallicpost or the semiconductor substrate, wherein the bump may be atantalum-containing metallic layer.

To achieve the abovementioned objectives, the present invention proposesa circuit structure and a fabrication method thereof. The circuitstructure of the present invention comprises: a semiconductor substrate;a metallic post, formed on the semiconductor substrate, and 20 to 300microns high with the ratio of the maximum horizontal dimension thereofto the height thereof less than 4; a first polymer layer, formed on thesemiconductor layer, and covering the metallic post; a substrate; abump, formed between the metallic post and the substrate or formedbetween the first polymer layer and the substrate; and a second polymerlayer, formed between the substrate and the semiconductor substrate, andcovering the bump.

To enable the objectives, technical contents, characteristics andaccomplishments of the present invention to be more easily understood,the embodiments of the present invention are to be described in detailin cooperation with the attached drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view schematically showing a conventionaltechnology.

FIG. 2 is a sectional view schematically showing a semiconductorsubstrate according to the present invention.

FIG. 3 is a sectional view schematically showing that a minuteconnection structure and a passivation layer are formed thesemiconductor substrate according to the present invention.

FIG. 4 a and FIG. 4 b are sectional views schematically showing thefabrication procedures of a first polymer layer according to the presentinvention.

FIG. 5 a is a sectional view schematically showing the fabricationprocedures of a first adhesion/barrier/seed layer according to thepresent invention.

FIG. 6 a to FIG. 6 e are sectional views schematically showing thefabrication procedures of a first RDL and metallic posts according tothe present invention.

FIG. 7 a and FIG. 7 b are respectively a sectional view schematicallyshowing the parameters of the metallic posts and a top viewschematically showing the metallic posts according to the presentinvention.

FIG. 8 a is a sectional view schematically showing the fabricationprocedures of a second polymer layer according to the present invention.

FIG. 8 b is a sectional view schematically showing the fabricationprocedures of the openings of the second polymer layer according to thepresent invention.

FIG. 8 c is a sectional view schematically showing the procedure ofpolishing the second polymer layer according to the present invention.

FIG. 9 is a sectional view schematically showing the fabricationprocedures of a third polymer layer according to the present invention.

FIG. 10 a to FIG. 10 d are sectional views schematically showing thefabrication procedures of a third metallic layer according to thepresent invention.

FIG. 11 is a sectional view schematically showing that the semiconductorsubstrate is diced according to the present invention.

FIG. 12 a to FIG. 12 c are sectional views schematically showing thefabrication procedures of solder balls according to the presentinvention.

FIG. 12 d and FIG. 12 e are sectional views respectively schematicallyshowing that the semiconductor substrate is diced and that thesemiconductor unit is joined to a substrate according to the presentinvention.

FIG. 13 a and FIG. 13 b are sectional views schematically showing thewire-bonding procedures of the metallic posts according to the presentinvention.

FIG. 14 a and FIG. 14 b are sectional views schematically showing theprocedures of forming a RDL on the metallic posts according to thepresent invention.

FIG. 15 a to FIG. 15 c are sectional views respectively schematicallyshowing the wire-bonded copper/nickel/gold metallic posts and thewire-bonded copper/gold metallic posts according to the presentinvention.

FIG. 16 a to FIG. 16 h are sectional views schematically showing thefabrication procedures of a first coil-like metallic layer formed abovethe metallic posts according to the present invention.

FIG. 16 g is a sectional view schematically showing the fabricationprocedures of a second coil-like metallic layer according to the presentinvention.

FIG. 16 h is a sectional view schematically showing the procedures offorming a capacitor element on the metallic posts according to thepresent invention.

FIG. 17 a to FIG. 17 d are sectional views schematically showing thefabrication procedures of a metallic layer to interconnect two metallicposts according to the present invention.

FIG. 17 e to FIG. 17 m are sectional views schematically showing theprocedures of forming a multi-layer circuit on the metallic postsaccording to the present invention.

FIG. 18 is a sectional view schematically showing the procedures offorming a resistor element on the metallic posts according to thepresent invention.

FIG. 19 a and FIG. 19 b are sectional views schematically showing that aportion of the second polymer layer is removed with an etching methodaccording to the present invention.

FIG. 19 c is a sectional view schematically showing that thesemiconductor substrate is diced according to the present invention.

FIG. 19 d and FIG. 19 e are sectional views respectively schematicallyshowing the procedures of forming solder balls and dicing thesemiconductor substrate according to the present invention.

FIG. 19 f is a sectional view schematically showing the procedures offorming contact pads according to the present invention.

FIG. 19 g to FIG. 19 k are sectional views schematically showing theprocedures of forming a metallic layer to interconnect two metallicposts according to the present invention.

FIG. 20 a is a sectional view schematically showing the procedures offorming a ninth patterned polymer layer on the semiconductor substrateaccording to the present invention.

FIG. 20 b to FIG. 20 d are sectional views schematically showing theprocedures of forming the metallic posts with a Damascene methodaccording to the present invention.

FIG. 21 a to FIG. 21 d are sectional views respectively schematicallyshowing the structures of the bump, contact pad, solder ball and RDLaccording to the present invention.

FIG. 22 to FIG. 25 are sectional views respectively schematicallyshowing the structures of the current freeway, coil, capacitor element,and resistor element according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention pertains to a circuit structure and a fabricationmethod thereof, wherein multiple metallic posts are formed on asemiconductor substrate, and the spacing between the neighboringmetallic posts is reduced to less than 250 μm. Below, severalembodiments are used to exemplify the present invention.

Embodiment 1

Refer to FIG. 2. Firstly, a semiconductor substrate 30 is provided, andthe semiconductor substrate 30 may be Si substrate, GaAs substrate, GeSisubstrate or SOI (silicon-on-insulator) substrate. In Embodiment 1, thesemiconductor substrate 30 is a circular semiconductor wafer. Thesemiconductor substrate 30 has an active surface having multipleelectronic elements 32, which are formed via doping trivalent orpentavalent ions, such as boron ions or phosphorus ions. The electronicelements 32 may be MOS transistors, MOS devices, p-channel MOS devices,n-channel MOS devices, BiCMOS devices, Bipolar Junction Transistors,diffusion areas, resistors, capacitors, or CMOS devices.

Refer to FIG. 3. A fine-line connection structure 34 is formed on theactive surface. The fine-line connection structure 34 comprises multiplethin-film insulating layers 36 having a thickness less than 3 μm andmultiple thin-film circuit layers 38 also having a thickness less than 3μm. The thin-film circuit layers 38 are made of a copper material or analuminum material. The thin-film insulating layers 36 are usually formedwith a CVD (Chemical Vapor Deposition) method. The material of thethin-film insulating layers 36 may be silicon oxide, TEOS(Tetraethoxysilane), SiwCxOyHz, compound of silicon andnitrogen/compound of silicon, nitrogen and oxygen, SOG (Spin-On Glass),FSG (Fluoro-Silicate Glass), SiLK, black diamond, polyarylene ether, PBO(Polybenzoxazole), or porous silicon oxide. The dielectric constant ofthe thin-film insulating layers 36 may be lower than 3.

When a damascene process is used to form one of multiple thin-filmcircuit layers 38 over the semiconductor substrate 30, adiffusion-barrier layer is firstly sputtered on the upper surface of oneof the thin-film insulating layers 36 and on the bottoms and the lateralwalls of the openings in said one of the thin-film insulating layers 36;next, a seed layer, such as a copper seed layer, is sputtered on thediffusion-barrier layer; next, a copper layer is electroplated on theseed layer; and then, the electroplated copper layer, seed layer anddiffusion-barrier layer outside the openings in said one of thethin-film insulating layers 36 are removed with a chemical mechanicalpolishing method until the upper surface of said one of the thin-filminsulating layers 36 is exposed. In another method to form one ofmultiple thin-film circuit layers 38 over the semiconductor substrate30, an aluminum layer or an aluminum alloy layer is sputtered on one ofthe thin-film insulating layers 36; and then, the aluminum layer or thealuminum alloy layer is patterned with a photolithographic process andan etching process. The thin-film circuit layers 38 can beinterconnected or connected to the electronic elements 32 via theconductive vias in the thin-film insulating layers 36. The thickness ofone of the thin-film circuit layers 38 is generally 0.1˜0.5 μm. Thethin-film circuit layers 38 are fabricated with a 5X stepper or 5Xscanner or other superior equipment in the step of a photolithographicprocess.

Next, a passivation layer 42 is formed over the semiconductor substrate30 with a CVD method. Multiple contact pads 44 are respectively exposedby openings in the passivation layer 42. The passivation layer 42 canprotect the electronic elements 32 on the semiconductor substrate 30from foreign ion contamination. The passivation layer 42 can retard thepenetration of mobile ions (such as sodium ions), moisture, transitionmetals (such as gold, silver, and copper) and impurities. Thereby, thepassivation layer 42 can protect the thin-film circuit layers 38, thethin-film insulating layers 36 and the underlying electronic elements 32including: transistors, polysilicon resistors, polysilicon-polysiliconcapacitors. The passivation layer 42 is usually composed of siliconoxide, compounds of silicon and oxygen, silicate and phosphate glass,silicon nitride, or silicon oxy-nitride, etc. Below, ten methods fordepositing the passivation layer 42 are to be introduced.

Method 1

A silicon oxide layer with a thickness of between 0.2 and 1.2 μm isformed with a CVD method; and next, a silicon nitride layer with athickness of between 0.2 and 1.2 μm is formed on the silicon oxide witha CVD method.

Method 2

A silicon oxide layer with a thickness of between 0.2 and 1.2 μm isformed with a CVD method; next, a silicon oxy-nitride layer with athickness of between 0.05 and 0.15 μm is formed on the silicon oxidewith a plasma-enhanced CVD method; and next, a silicon nitride layerwith a thickness of between 0.2 and 1.2 μm is formed on the siliconoxy-nitride layer with a CVD method.

Method 3

A silicon oxy-nitride layer with a thickness of between 0.05 and 0.15 μmis formed with a CVD method; next, a silicon oxide layer with athickness of between 0.2 and 1.2 μm is formed on the silicon oxy-nitridelayer with a CVD method; and next, a silicon nitride layer with athickness of between 0.2 and 1.2 μm is formed on the silicon oxide layerwith a CVD method.

Method 4

A first silicon oxide layer with a thickness of between 0.2 and 0.5 μmis formed with a CVD method; next, a second silicon oxide layer with athickness of between 0.5 and 1 μm is formed on the first silicon oxidelayer with a spin-coating method; next, a third silicon oxide layer witha thickness of between 0.2 and 0.5 μm is formed on the second siliconoxide layer with a CVD method; and next, a silicon nitride layer with athickness of between 0.2 and 1.2 μm is formed on the third silicon oxidelayer with a CVD method.

Method 5

A silicon oxide layer with a thickness of between 0.5 and 2 μm is formedwith a HDP-CVD (High Density Plasma-Chemical Vapor Deposition) method;and next, a silicon nitride layer with a thickness of between 0.2 and1.2 μm is formed on the silicon oxide layer with a CVD method.

Method 6

A USG (Undoped Silicate Glass) layer with a thickness of between 0.2 and3 μm is firstly formed; next, an insulating layer with a thickness ofbetween 0.5 and 3 μm, such as TEOS, BPSG (Borophosphosilicate Glass) orPSG (Borophosphosilicate Glass), is formed on the USG layer; and next, asilicon nitride layer with a thickness of between 0.2 and 1.2 μm isformed on the insulating layer with a CVD method.

Method 7

A first silicon oxy-nitride layer with a thickness of between 0.05 and0.15 μm is optionally formed with a CVD method; next, a silicon oxidelayer with a thickness of between 0.2 and 1.2 μm is formed on the firstsilicon oxy-nitride layer with a CVD method; next, a second siliconoxy-nitride layer with a thickness of between 0.05 and 0.15 μm isoptionally formed on the silicon oxide layer with a CVD method; next, asilicon nitride layer with a thickness of between 0.2 and 1.2 μm isformed on the second silicon oxy-nitride layer or on the silicon oxidelayer with a CVD method; next, a third silicon oxy-nitride layer with athickness of between 0.05 and 0.15 μm is optionally formed on thesilicon nitride layer with a CVD method; and next, a silicon oxide layerwith a thickness of between 0.2 and 1.2 μm is formed on the thirdsilicon oxy-nitride layer or on the silicon nitride layer with a CVDmethod.

Method 8

A first silicon oxide layer with a thickness of between 0.2 and 1.2 μmis formed with a PECVD (Plasma Enhanced Chemical Vapor Deposition)method; next, a second silicon oxide layer with a thickness of between0.5 and 1 μm is formed on the first silicon oxide layer with aspin-coating method; next, a third silicon oxide layer with a thicknessof between 0.2 and 1.2 μm is formed on the second silicon oxide layerwith a CVD method; next, a silicon nitride layer with a thickness ofbetween 0.2 and 1.2 μm is formed on the third silicon oxide layer with aCVD method; and next, a fourth silicon oxide layer with a thickness ofbetween 0.2 and 1.2 μm is formed on the silicon nitride layer with a CVDmethod.

Method 9

A first silicon oxide layer with a thickness of between 0.5 and 2 μm isformed with a HDP-CVD method; next, a silicon nitride layer with athickness of between 0.2 and 1.2 μm is formed on the first silicon oxidelayer with a CVD method; and next, a second silicon oxide layer with athickness of between 0.5 and 2 μis formed on the silicon nitride layerwith a HDP-CVD method.

Method 10

A first silicon nitride layer with a thickness of between 0.2 and 1.2 μmis formed with a CVD method; next, a silicon oxide layer with athickness of between 0.2 and 1.2 μm is formed on the first siliconnitride layer with a CVD method; and next, a second silicon nitridelayer with a thickness of between 0.2 and 1.2 μm is formed on thesilicon oxide layer with a CVD method.

The thickness of the passivation layer 42 is generally more than 0.35μm, and the thickness of the silicon nitride layer is generally morethan 0.3 μm under an optimal condition.

Refer to FIG. 4 a. After the passivation layer 42 has been completed, afirst polymer layer 46 with a thickness of between 3 and 50 μm is formedon the passivation layer 42 and used for insulating. The material of thefirst polymer layer 46 is thermoplastic, thermosetting plastic,polyimide, BCB (Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-basedpolymer, solder-mask material, elastic material, or porous dielectricmaterial. The method of forming the first polymer layer 46 includesspin-coating an oligomer film on the passivation layer 42. Refer to FIG.4 b. Next, the spun-on oligomer layer 46 with a photosensitive materialis patterned with a photolithography method to form multiple openings 48in the olgomer layer 46 exposing the contact pads 44 on thesemiconductor substrate 30. It is to be noted: when the first polymerlayer 46 is made of a photosensitive material, it can be patterned witha photolithographic process; when the first polymer layer 46 is made ofa non-photosensitive material, it can be patterned with aphotolithographic process and an etching process.

Next, the patterned oligomer layer 46 is cured via heating it to thetemperature of 200˜320° C. with a baking method, a microwave heatingmethod, or an infrared heating method or to the temperature of 320˜450°C. The cured first polymer layer 46 has a dimensional shrinkage and amoisture content less than 1%, which is determined via that the weightvariation is less than 1% when the first polymer layer 46 is placed atthe temperature of 425˜450° C. Alternatively, the method of forming thefirst polymer layer 46 includes: laminating a dry film with aphotosensitive material on the passivation layer 42 with a heat-pressingmethod and then forming openings in the dry film using aphotolithography method; or screen-printing an oligomer film on thepassivation layer 42 with multiple openings in the oligomer filmexposing the contact pads 44, and then curing the oligomer film using aheating process.

Refer to FIG. 5. A first adhesion/barrier layer 50 with a thickness ofbetween 400 and 7000 Å is formed on the first polymer layer 46 and thecontact pads 44 with a sputtering method. The material of the firstadhesion/barrier layer 50 is titanium metal, titanium nitride,titanium-tungsten alloy, chromium metal, chromium-copper alloy, tantalummetal, or tantalum nitride. Alternatively, the first adhesion/barrierlayer 50 may be a composite of the above-mentioned materials. Next, Aseed layer (not shown) with a thickness of between 500 and 5000angstroms may be formed on the first adhesion/barrier layer 50 using asputtering process. The seed layer is used to benefit the formation ofthe succeeding metallic wires; therefore, the material of the seed layervaries with the material to be used by the succeeding metallic wires.

When a copper metallic wire is to be electroplated on the seed layer,copper is a preferable material to the seed layer. When a silvermetallic wire is to be electroplated on the seed layer, silver is apreferable material to the seed layer. When a palladium metallic wire isto be electroplated on the seed layer, palladium is a preferablematerial to the seed layer. When a platinum metallic wire is to beelectroplated on the seed layer, platinum is a preferable material tothe seed layer. When a rhodium metallic wire is to be electroplated onthe seed layer, rhodium is a preferable material to the seed layer. Whena ruthenium metallic wire is to be electroplated on the seed layer,ruthenium is a preferable material to the seed layer. When a rheniummetallic wire is to be electroplated on the seed layer, rhenium is apreferable material to the seed layer. When a nickel metallic wire is tobe electroplated on the seed layer, nickel is a preferable material tothe seed layer.

Refer to FIG. 6 a. Next, a first patterned photoresist layer 54 isformed on the seed layer on the first adhesion/barrier layer 50.Multiple openings 56 is formed in the first patterned photoresist layer54 with a 1X stepper or 1X scanner. The first patterned photoresistlayer 54 is a positive photoresist, for example. The openings 56 exposethe seed layer on the first adhesion/barrier layer 50. Next, a firstmetallic layer 58 with a thickness of between 1 and 50 μm iselectroplated on the seed layer 50 formed on the first adhesion/barrierlayer 50 and exposed by the openings 56, and the thickness of the firstmetallic layer 58 is preferred to be 2˜30 μm. Thereby, the firstmetallic layer 58 is electrically connected to the thin-film circuitlayers 34. The first metallic layer 58 may be a single layer of gold,copper, silver, palladium, platinum, rhodium, ruthenium, rhenium, ornickel. Alternatively, the first metallic layer 58 may be a composite ofthe above-mentioned materials. Next, the first patterned photoresistlayer 54 is removed. The first metallic layer 58 is not only simplyformed inside the openings 48 but also extended to some portions overthe first polymer layer 46. The extended first metallic layer 58 canbenefit the formation of the succeeding metal posts.

Next, as shown in FIG. 6 b, a second patterned photoresist layer 62 isformed on the first metallic layer 58 and the seed layer on theadhesion/barrier layer 50. Multiple openings 64 in the second patternedphotoresist layer 62 expose the first metallic layer 58. Next, as shownin FIG. 6 c, a second metallic layer 66 with a thickness of between 20and 200 μm is formed on the first metallic layer 58 exposed by theopenings 64 via electroplating, and the maximum horizontal dimension ofeach metal post 66 ranges from 3 to 50 μm. The second metallic layer 66serves as metal posts. The material of the second metallic layer 66 maybe a single metal layer of gold, copper, silver, palladium, platinum,rhodium, ruthenium, rhenium, or nickel. Alternatively, the secondmetallic layer 66 may be a composite of the above-mentioned materials.The thickness of the second metallic layer 66 is preferred to be 30 to100 microns.

When a second metallic layer 66 of copper is to be electroplated on thefirst metallic layer 58, copper is a preferable material to the topmostlayer of the first metallic layer 58. When a second metallic layer 66 ofsilver is to be electroplated on the first metallic layer 58, silver isa preferable material to the topmost layer of the first metallic layer58. When a second metallic layer 66 of palladium is to be electroplatedon the first metallic layer 58, palladium is a preferable material tothe topmost layer of the first metallic layer 58. When a second metalliclayer 66 of platinum is to be electroplated on the first metallic layer58, platinum is a preferable material to the topmost layer of the firstmetallic layer 58. When a second metallic layer 66 of rhodium is to beelectroplated on the first metallic layer 58, rhodium is a preferablematerial to the topmost layer of the first metallic layer 58. When asecond metallic layer 66 of ruthenium is to be electroplated on thefirst metallic layer 58, ruthenium is a preferable material to thetopmost layer of the first metallic layer 58. When a second metalliclayer 66 of rhenium is to be electroplated on the first metallic layer58, rhenium is a preferable material to the topmost layer of the firstmetallic layer 58. When a second metallic layer 66 of nickel is to beelectroplated on the first metallic layer 58, nickel is a preferablematerial to the topmost layer of the first metallic layer 58.

Next, as shown in FIG. 6 d, the second patterned photoresist layer 62 isremoved; next, the seed layer and the first adhesion/barrier layer 50not under the first metallic layer 58 are subsequently removed using anetching process. If the first adhesion/barrier layer 50 is titaniumtungsten alloy, the etchant for etching the first adhesion/barrier layer50 can be hydrogen peroxide. If the seed layer is gold, the etchant foretching the seed layer is potassium iodide. As shown in FIG. 6 e, thestep of removing the seed layer and the first adhesion/barrier layer 50not under the first metallic layer 58 may be undertaken before formingthe metal Posts 68.

As shown in FIG. 7 a and FIG. 7 b, The ratio of the maximum horizontaldimension Hw of the metallic post 66 to the height Ht of the metallicpost 66 is less than 4, and the ratio may also be less than 3, 2 or 1.The maximum horizontal dimension of the metallic post 68 is within 3˜50microns; therefore, the metallic post 66 is a fine post, which isdistinct from the conventional technology. The pitch Hb between thecenters of the neighboring metallic posts 68 is 10˜250 microns, and thepreferable spacing Hb is 10˜200 microns, 10˜175 microns, or 10˜150microns. FIG. 7 b is a top view showing that the metallic Posts 68 areimplemented with the redistribution layer 60 composed of the firstadhesion/barrier layer 50 and the first metallic layer 58. From FIG. 7b, it can be observed that the metallic post 66 is not formed on theredistribution layer 60 over the openings 48 but formed on theredistribution layer 60 over the first polymer layer 46.

Next, as shown in FIG. 8 a, a second polymer layer 70 is formed over thesemiconductor substrate 30 and covers the metallic Posts 68 and theredistribution layer 60. The material of the second polymer layer 70 maybe thermoplastic, thermosetting plastic, polyimide, BCB(Benzo-Cyclo-Butene), polyurethane, epoxy, parylene polymer, solder-maskmaterial, elastic material, or porous dielectric material. The methodsof forming the second polymer layer 70 may include a screen-printingmethod or a spin-coating method. As shown in FIG. 8 b, if the secondpolymer layer 70 is formed with a screen-printing method, multipleopenings 72, whereby the top ends of the metallic Posts 68 are revealed,can be formed in the second polymer layer 70 just when screen printingthe second polymer layer 70. If the second polymer layer 70 is formedwith a spin-coating method, multiple openings 72, whereby the top endsof the metallic Posts 68 are revealed, must be fabricated with apatterning procedure, such as a photolithographic method or aphotolithographic method plus an etching method. As shown in FIG. 8 c,beside via the openings 72, the metallic Posts 68 may also be revealedvia a polishing method. However, the second polymer layer 70 needscuring before the polishing procedure. After the second polymer layer 70has been cured, a CMP (Chemical Mechanical Polishing) procedure ormechanical grinding to polish or grind the second polymer layer 70 isused to reveal the top ends of the metallic Posts 68. The curingprocedure may also be undertaken with a baking method, a microwaveheating method, or an infrared heating method under the temperature ofbetween 200 and 320 degrees centigrade or between 320 and 400 degreescentigrade.

Here, it is to be stated beforehand that the structures of the followingembodiments are predominantly the extensions of the structures shown inFIG. 8 b and FIG. 8 c, wherein the metallic Posts 68 has a fine pitch,and the spacing between the centers of the neighboring metallic Posts 68is within 10˜250 microns; the ratio of the maximum horizontal dimensionof the metallic post 66 Hw to the height of the metallic post 66 Ht isless than 4. The first embodiment is based on the structure illustratedin FIG. 8 c, and the succeeding embodiments are usually with respect tothe variations of the metallic post 66.

Next, as shown in FIG. 9, a third polymer layer 74 is formed on thesecond polymer layer 70 using a spin coating process. Multiple openings76 are formed in the third polymer layer 74 with a patterning procedure,wherein the patterning procedure is undertaken with a photolithographicmethod or a photolithographic method plus an etching method.Alternatively, the method of forming the first polymer layer 46includes: laminating a dry film with a photosensitive material on thepassivation layer 42 with a heat-pressing method and then formingopenings in the dry film using a photolithography method; orscreen-printing an oligomer film on the passivation layer 42 withmultiple openings in the oligomer film exposing the contact pads 44, andthen curing the oligomer film using a heating process. The material ofthe third polymer layer 74 is thermoplastic, thermosetting plastic,polyimide, BCB (Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-basedpolymer, solder-mask material, elastic material, or porous dielectricmaterial. The metallic posts 68 have a same structure as theprevious-mentioned metallic Posts 68. The process for forming themetallic posts 68 is the same as that for forming the previouslymentioned metallic Posts 68.

Next, as shown in FIG. 10 a, a second adhesion/barrier layer with athickness of between 400 and 7000 Å is formed on the third polymer layer74 and the top ends of the metallic posts 68 with a sputtering method.The material of the second adhesion/barrier layer 78 is titanium metal,titanium nitride, titanium-tungsten alloy, chromium metal,chromium-copper alloy, tantalum metal, or tantalum nitride.Alternatively, the second adhesion/barrier layer 78 may also be acomposite of the above-mentioned materials. Next, A seed layer (notshown), such as copper or gold, with a thickness of between 500 and 5000angstroms may be formed on the second adhesion/barrier layer 78 using asputtering process. Next, as shown in FIG. 10 b, a third patternedphotoresist layer 82 is formed on the seed layer on the secondadhesion/barrier layer 78, wherein the third patterned photoresist layer82 is a positive-type photoresist. Multiple openings 83 in the thirdpatterned photoresist layer 82 expose the seed layer on the secondadhesion/barrier layer 78 over the top ends of the metal posts 68.

Next, as shown in FIG. 10 c, a third metallic layer 84 is formed on theseed layer on the second adhesion/barrier layer 78 exposed by theopenings 83 via electroplating. The third metallic layer 84 may beformed by electroplating a gold layer having a thickness of between 1and 50 microns on the seed layer, made of gold, exposed by the openings83. Other materials used to form the third metallic layer 84 may besilver, palladium, platinum, rhodium, ruthenium, or rhenium. Next, asshown in FIG. 10 d, the third patterned photoresist layer 82 is removed;next, the seed layer and the underlying second adhesion/barrier layer 78are subsequentially removed. If the second adhesion/barrier layer 78 istitanium tungsten alloy, the etchant for etching the secondadhesion/barrier layer 78 can be hydrogen peroxide. If the seed layer isgold, the etchant for etching the seed layer is potassium iodide. It isto be noted that the thickness, material and position of theelectroplated third metallic layer 84 is determined by which types ofexternal devices or circuits are connected to the bumps or pads 84, i.e.the thickness of the third patterned photoresist layer 82, the width ofthe openings 83 and the position of the openings 83 vary according tothe intended application. The abovementioned external circuit may be aflexible circuit board, a semiconductor chip, a printed circuit board, aceramic substrate, or a glass substrate.

In this embodiment, the third metallic layer 84 may be presented in theform of bumps, contact pads, RDL's, or solder balls. As shown in FIG. 10d, when the third metallic layer 84 is a single layer of gold, copper,silver, palladium, platinum, rhodium, ruthenium, or rhenium, and whenthe thickness Ha of the third metallic layer 84 is 5˜30 microns andpreferably is 10˜25 microns, the third metallic layer 84 is defined tobe a bump 86. Next, as shown in FIG. 11, the semiconductor substrate 30is diced into multiple semiconductor units 88. The bumps 86 on thesemiconductor unit 88 can be electrically connected to an externalcircuit with ACF (Anisotropic Conductive Film).

Refer to FIG. 12 a, FIG. 12 b and FIG. 12 c. When the third metalliclayer 84 has a solder layer, such as a tin-lead alloy, a tin-silveralloy, a tin-silver-copper alloy or lead-free solder, and has athickness Hs of between 20 and 150 microns, and preferably between 30and 100 microns, the semiconductor substrate 30 can be heated to reflowthe solder layer of the third metallic layer 84 with the a ball shape,which is defined to be a solder ball 92. The third metallic layer 84 maybe formed by electroplating a copper layer having a thickness of between1 and 100 microns on the seed layer, made of copper, exposed by theopenings 83, next electroplating a nickel layer having a thickness ofbetween 1 and 10 microns on the copper layer exposed by the openings 83,and next electroplating a tin-containing solder layer, such as atin-lead alloy, a tin-silver alloy or a tin-silver-copper alloy, havinga thickness of between 20 and 150 microns on the nickel layer. Next, asshown in FIG. 12 d, the semiconductor substrate 30 is diced intomultiple semiconductor units 88. The solder balls 92 on thesemiconductor unit 88 can be electrically connected to an externalsubstrate 94, as shown in FIG. 12 e. The external substrate 94 may be asemiconductor chip, a printed circuit board, a ceramic substrate, or aglass substrate. The distance between the centers of the neighboringsolder balls 92 may be between 10 and 250 microns.

As shown in FIG. 12 e, before the solder balls 92 on the semiconductorunit 88 are connected to substrate 94, a fourth polymer layer 96 may beformed on the substrate 94 beforehand. The material of the fourthpolymer layer 96 is thermoplastic, thermosetting plastic, polyimide, BCB(Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-based polymer,solder-mask material, elastic material, or porous dielectric material.The fourth polymer layer 96 may be formed on the substrate 94 bylaminating a patterned dry film on the substrate 94 using aheat-pressing method, or by laminating a photosensitive dry film on thesubstrate 94 using a heat-pressing method and patterning thephotosensitive dry film with a photolithographic method, or bylaminating a non-photosensitive dry film on the substrate 94 using aheat-pressing method and patterning the non-photosensitive dry film witha photolithographic method plus an etching method, or by screen-printingthe fourth polymer layer 96 where multiple openings are simultaneouslyformed in the fourth polymer layer 96, or by spin-coating aphotosensitive film on the substrate 94 and then patterning thephotosensitive film with a photolithographic method, or by spin-coatinga non-photosensitive film on the substrate 94 and patterning thenon-photosensitive film with a photolithographic method plus an etchingmethod. After the solder balls 92 on the semiconductor unit 88 areattached to substrate 94, a heating procedure is used to cure the fourthpolymer layer 96. The curing procedure is undertaken with a bakingmethod, a microwave heating method, or an infrared heating method.

Refer to FIG. 13 a and FIG. 13 b. When the third metallic layer 84 is asingle layer made of gold, copper, silver, palladium, platinum, rhodium,ruthenium, or rhenium, and has a thickness Hp of between 1 and 15microns and preferably between 2 and 10 microns, the third metalliclayer 84 is defined to be a contact pad 98. The contact pads 98 can beconnected to an external circuit with wires formed by a wire bondingprocess.

Refer to FIG. 14 a and FIG. 14 b. When the third metallic layer 84 ismade of gold, copper, silver, palladium, platinum, rhodium, ruthenium,or rhenium, and has a thickness Hr of between 5 and 30 microns, andpreferably between 10 and 25 microns, the third metallic layer 84 maydefined to be a metal trace 100. The metal trace has a relocated padconnected to the metal post 68, wherein the position of the relocatedpad and the metal post 68 connected thereto from a top surface isdifferent. The relocated pad of the metal trace 100 can be connected toan external circuit with wires formed by a wire-bonding process. Thedistance between the centers of the wirebonding pads 92 may be between10 and 250 microns.

In this embodiment, the structures having the bumps, contact pads,RDL's, and solder balls shown in from FIG. 9 to FIG. 14 b are all thestructures derived from the structure shown in FIG. 8 c. However, thosestructures may also be derived from the structure shown in FIG. 8 b. Thestructure shown in FIG. 9 is fabricated via forming the third polymerlayer 74 on the structure shown in FIG. 8 c and patterning the thirdpolymer layer 74 to form multiple openings in the third polymer layer74. In the structure shown in FIG. 8 b, the metallic posts 68 are notrevealed via polishing the second polymer layer 70 but revealed viaforming multiple openings in the second polymer layer 70 with apatterning procedure. It is unnecessary to form the third polymer layer74 for the structure shown in FIG. 8 b. The structure shown in FIG. 8 bis equivalent to the structure shown in FIG. 8 c plus the third polymerlayer 74. Therefore, the above-mentioned for forming the bumps, contactpads, metal traces, and solder balls derived from FIG. 9, as shown inFIGS. 10 a-10 d, 11, 12 a-12 e, 13 a-13 b and 14 a-14 b, also can beapplied to the structure shown in FIG. 8 b.

Embodiment 2

This embodiment is derived from the structure of Embodiment 1 shown inFIG. 8 c. As shown in FIG. 15 a, the top end of the metallic post 68 isa gold layer 102 having a thickness of between 1 and 30 microns, and awire formed with a wire-bonding process can be connected onto the goldlayer 102 of the metallic post 68. It is to be noted: a nickel layer 106having a thickness of between 1 and 10 microns and a copper layer 104having a thickness of between 10 and 100 microns and are sequentiallybelow the gold layer 102 to form a copper/nickel/gold structure for themetal post 68. Alternatively, as shown in FIG. 15 b, a copper layer 104having a thickness of between 10 and 100 microns is below the gold layer102 having a thickness of between 1 and 30 microns to form a copper/goldstructure for the metal post 68. Alternatively, as shown in FIG. 15 c,the entire metallic post 68 having a thickness of between 10 and 100microns may be made of gold.

Embodiment 3

This embodiment is derived from the structure of Embodiment 1 shown inFIG. 8 c. As shown in FIG. 16 a, a third adhesion/barrier layer 105 isformed on the second polymer layer 70 and on the top end of the metalpost 68. The material of the third adhesion/barrier layer 105 istitanium metal, titanium nitride, titanium-tungsten alloy, chromiummetal, chromium-copper alloy, tantalum metal, or tantalum nitride. Aseed layer (not shown), such as gold, copper, silver, nickel, platinum,palladium, ruthenium, rhodium, or rhenium, may be sputtered on the thirdadhesion/barrier layer 105. As shown in FIG. 16 b, a fourth patternedphotoresist layer 110 is formed on the seed layer on the thirdadhesion/barrier layer 105; a coil-shaped opening 112 in the fourthpatterned photoresist layer 110 exposes the seed layer on theadhesion/barrier layer 105. As shown in FIG. 16 c, a fourth metalliclayer 114 is electroplated on the seed layer exposed by the opening 112in the fourth patterned photoresist layer 110. The fourth metallic layer114 may be formed by electroplating a single layer of gold, copper,silver, nickel, platinum, palladium, ruthenium, rhodium, or rhenium,having a thickness of between 1 and 30 microns. Alternatively, thefourth metallic layer 114 may be formed by electroplating a copper layerhaving a thickness of between 1 and 30 microns, next electroplating anickel layer having a thickness of between 1 and 10 microns on thecopper layer, and next electroplating a gold layer having a thickness ofbetween 1 and 10 microns on the nickel layer. Preferably, the bottommostmetal layer of the fourth metallic layer 114 has a same material as theseed layer. As shown in FIG. 16 d, the fourth patterned photoresistlayer 110 is removed; and next the seed layer and the thirdadhesion/barrier layer 105 not under the fourth metallic layer 114 areremoved. If the third adhesion/barrier layer 105 is titanium tungstenalloy, the etchant for etching the third adhesion/barrier layer 105 canbe hydrogen peroxide. If the seed layer is gold, the etchant for etchingthe seed layer is potassium iodide. As shown in FIG. 16 e, the fourthmetallic layer 114 appears like a coil; thus, the fourth metallic layer114 is defined to be a first coil-like metallic layer 116. As shown inFIG. 16 f, the metallic posts 68 electrically connect the firstcoil-like metallic layer 116 to the semiconductor substrate 30; thefirst coil-like metallic layer 116 may also be electrically connected toan external circuit via a wire-bonding process; a protection layer 117having a thickness of between 5 and 25 microns may be formed above thefirst coil-like metallic layer 116 lest the first coil-like metalliclayer 16 be damaged or penetrated by moisture. The material of theprotection layer 117 may be an organic or inorganic material or may bethermoplastic, thermosetting plastic, polyimide, BCB(Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-based polymer,solder-mask material, elastic material, porous dielectric material,silicon oxide, compounds of silicon and oxygen, silicate and phosphateglass, silicon nitride, or silicon oxy-nitride. The first coil-likemetallic layer 116 may be used as a passive device, such as an inductor.

The case that the first coil-like metallic layer 116 is applied to aninductor is to be exemplified here. As shown in FIG. 16 g, a fifthpolymer layer 118, such as polyimide or benzo-cyclo-butene (BCB), havinga thickness of between 20 and 200 microns is formed to cover the firstcoil-like metallic layer 116. The fifth polymer layer 118 may be formedby spin coating multiple oligomer layers each having a thickness ofbetween 10 and 25 microns or screen-printing a thick oligomer layer. Asecond coil-like metallic layer 120 is formed on the fifth polymer layer118 with the same method as that used to form the first coil-likemetallic layer 116. The second coil-like metallic layer 120 iselectrically connected to an external circuit. When there is a currentvariation in the external circuit, an electromotive force is induced inthe first coil-like metallic layer 116 by the current through the secondcoil-like metallic layer 120, thereby creating a signal transmitted tothe semiconductor substrate 30.

The abovementioned selective electroplating may also be used to form acapacitor element 121 on the second polymer layer 70. As shown in FIG.16 h, a low-permittivity layer 121 a with a thickness of between 500 and5000 Å is formed on the second polymer layer 70. The material of thelow-permittivity layer 121 a is titanium metal, titanium-tungsten alloy,tantalum metal, or tantalum nitride, etc. The low-permittivity layer 121a is electrically connected to one of the metallic posts 68. Next, ahigh-permittivity layer 121 b is formed on the low-permittivity layer121 a. The material of the high-permittivity layer 121 b is siliconoxy-nitride, silicon oxide, or polyimide. A low-resistance layer 121 cis formed on the high-permittivity layer 121 b and connected to theother one of the metallic posts 68. The low-resistance layer 121 c maybe fabricated by sputtering an adhesion/barrier layer, such as titanium,titanium-tungsten alloy, chromium, tantalum or tantalum nitride, havinga thickness of between 400 and 7500 angstroms on the high-permittivitylayer 121 b, next sputtering a seed layer, preferably made of copper,having a thickness of between 500 and 5000 angstroms on theadhesion/barrier layer, next electroplating a copper layer having athickness of between 1 and 30 microns on the seed layer, next optionallyelectroplating a nickel layer having a thickness of between 1 and 10microns on the copper layer, and next optionally electroplating a goldlayer having a thickness of between 1 and 10 microns on the nickel layeror on the copper layer. Alternatively, the low-resistance layer 121 cmay be fabricated by sputtering an adhesion/barrier layer, such astitanium, titanium-tungsten alloy, chromium, tantalum or tantalumnitride, having a thickness of between 400 and 7500 angstroms on thehigh-permittivity layer 121 b, next sputtering a seed layer, preferablymade of gold, having a thickness of between 500 and 5000 angstroms onthe adhesion/barrier layer, next electroplating a gold layer having athickness of between 1 and 30 microns on the seed layer. A protectionlayer 121 d is formed on the low-resistance layer 121 c and the secondpolymer layer 70 lest the capacitor element 121 be damaged. The materialof the protection layer 121 d may be an organic or inorganic material ormay be thermoplastic, thermosetting plastic, polyimide, BCB(Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-based polymer,solder-mask material, elastic material, porous dielectric material,silicon oxide, compounds of silicon and oxygen, silicate and phosphateglass, silicon nitride, or silicon oxy-nitride.

Embodiment 4

This embodiment is derived from the structure of Embodiment 1 shown inFIG. 8 b. As shown in FIG. 17 a, a fourth adhesion/barrier layer 122,such as titanium, titanium tungsten alloy, chromium, tantalum ortantalum nitride, is formed on the second polymer layer 70 and on thetop ends of the metal posts 68 using a sputter process. A seed layer,such as gold, copper, silver, nickel, platinum, palladium, ruthenium,rhodium, or rhenium, is sputtered on the fourth adhesion/barrier layer122. As shown in FIG. 17 b, a fifth patterned photoresist layer 126 isformed on the seed layer on the fourth adhesion/barrier layer 122. Atrace-shaped opening 128 in the fifth patterned photoresist layer 126exposes the seed layer on the fifth patterned photoresist layer 126. Asshown in FIG. 17 c, a fifth metallic layer 130 having a thickness ofbetween 5 and 30 microns is electroplated on the seed layer on thefourth adhesion/barrier layer 122 exposed by the opening 128 in thefifth patterned photoresist layer 126; the fifth metallic layer 130 ismade of a low-resistance material, such as gold, silver or copper. Thefifth metallic layer 130 may be formed by electroplating a single layerof gold, copper, silver, nickel, platinum, palladium, ruthenium,rhodium, or rhenium, having a thickness of between 1 and 30 microns.Alternatively, the fifth metallic layer 130 may be formed byelectroplating a copper layer having a thickness of between 1 and 30microns, next electroplating a nickel layer having a thickness ofbetween 1 and 10 microns on the copper layer, and next electroplating agold layer having a thickness of between 1 and 10 microns on the nickellayer. Preferably, the bottommost metal layer of the fifth metalliclayer 130 has a same material as the seed layer. As shown in FIG. 17 d,the fifth patterned photoresist layer 126 is removed, and next the seedlayer and the fourth adhesion/barrier layer 122 not under the fifthmetallic layer 130 are etched away. If the third adhesion/barrier layer105 is titanium tungsten alloy, the etchant for etching the thirdadhesion/barrier layer 105 can be hydrogen peroxide. If the seed layeris gold, the etchant for etching the seed layer is potassium iodide. Thefifth metallic layer 130 is electrically connected to two metallic posts68 and functions as the interconnection between multiple metallic posts68. A protection layer 132 is formed to cover the second polymer layer70 and the fifth metallic layer 130 lest the fifth metallic layer 130 bedamaged or penetrated by moisture. The material of the protection layer132 may be an organic or inorganic material or may be thermoplastic,thermosetting plastic, polyimide, BCB (Benzo-Cyclo-Butene),polyurethane, epoxy, parylene-based polymer, solder-mask material,elastic material, porous dielectric material, silicon oxide, compoundsof silicon and oxygen, silicate and phosphate glass, silicon nitride, orsilicon oxy-nitride.

In addition to the fifth metallic layer 130 functioning as theinterconnection between the metallic posts 68, multi-layer wirestructure may also be fabricated thereby. The metal trace 130 may not beconnected up to an external circuitry, but be connected down totransistors or MOS devices. As shown in FIG. 17 e, a sixth polymer layer134, such as polyimide or benzo-cyclo-butene (BCB), having a thicknessof between 10 and 25 microns is formed on the second polymer layer 70and on the fifth metallic layer 130. Provided that the metal trace 130may not be connected up to an external circuitry, but be connected downto transistors or MOS devices, an opening in the sixth polymer layer 134exposing the metal trace 130 is not necessary. Next, as shown in FIG. 17f, the sixth polymer layer 134 is patterned to form multiple openings inthe sixth polymer layer 134, whereby the fifth metallic layer 130 isrevealed. As shown in FIG. 17 g, a fifth adhesion/barrier layer 136,such as titanium, titanium tungsten alloy, chromium, tantalum ortantalum nitride, is formed on the sixth polymer layer 134 and on themetal trace 130 with a sputtering method. Next, a seed layer (notshown), such as gold, copper, silver, nickel, platinum, palladium,ruthenium, rhodium, or rhenium, is sputtered on the fifthadhesion/barrier layer 136. As shown in FIG. 17 h, a sixth patternedphotoresist layer 140 is formed on the seed layer on the fifthadhesion/barrier layer 136, an opening in the sixth patternedphotoresist layer 140 expose the seed layer on the fifthadhesion/barrier layer 136. As shown in FIG. 17 i, a sixth metalliclayer 142 is formed on the seed layer exposed by the opening in thesixth patterned photoresist layer 140. The sixth metallic layer 142 maybe formed by electroplating a single layer of gold, copper, silver,nickel, platinum, palladium, ruthenium, rhodium, or rhenium, having athickness of between 1 and 30 microns. Alternatively, the sixth metalliclayer 142 may be formed by electroplating a copper layer having athickness of between 1 and 30 microns, next electroplating a nickellayer having a thickness of between 1 and 10 microns on the copperlayer, and next electroplating a gold layer having a thickness ofbetween 1 and 10 microns on the nickel layer. Preferably, the bottommostmetal layer of the sixth metallic layer 142 has a same material as theseed layer. As shown in FIG. 17 j, the sixth patterned photoresist layer140 is removed; next, the seed layer and the fifth adhesion/barrierlayer 136 not under the sixth metallic layer 142 are sequentiallyremoved. As shown in FIG. 17 k, a seventh polymer layer 144, such aspolyimide or benzo-cyclo-butene (BCB), having a thickness of between 10and 25 microns is formed on the sixth polymer layer 134 and the sixthmetallic layer 142. As shown in FIG. 17 l, the seventh polymer layer 144is patterned to form multiple openings in the seventh polymer layer 144exposing the sixth metallic layer 142. As shown in FIG. 17 m, therevealed sixth metallic layer 142 may be electrically connected to anexternal circuit with a wire formed by a wire-bonding process, or with asolder bump or gold bump.

Embodiment 5

This embodiment is derived from the structure of Embodiment 1 shown inFIG. 8 b and is similar to Embodiment 4. Refer to FIG. 18. Thefabrication method of this embodiment is similar to that of Embodiment4. In Embodiment 4, the fifth metallic layer 130 is made of alow-resistance material and used as a contact pad. However, inEmbodiment 5, the seventh metallic layer 146 is made of ahigh-resistance material, such as chromium-nickel alloy, titanium ortungsten, and is only 1˜3 microns thick and functions as a resistorelement.

Embodiment 6

This embodiment is derived from the structure shown in FIG. 8 a. Asshown in FIG. 19 a and FIG. 19.b, in this embodiment, the second polymerlayer 70 is removed by first chemical mechanical polishing or mechanicalgrinding the second polymer layer 70, and then etching the secondpolymer layer 70 until the top ends and the upper portion of the sidewalls of the metal posts 68 are revealed. The distance from the top endof the metallic post 68 to the top surface of the second polymer layer70 may range from 1 to 150 microns. When the topmost metal layer of themetallic post 68 is gold, copper, silver, palladium, platinum, rhodium,ruthenium, or rhenium, and the distance from the top end of the metallicpost 68 to the top surface of the second polymer layer 70 may range from15 to 30 microns, the revealed portion of the metallic post 68 mayfunction as a bump. As shown in FIG. 19 c, thereafter, the semiconductorsubstrate 30 may be similarly diced into multiple semiconductor units88. The bumps on the semiconductor unit 88 can be similarly electricallyconnected to an external circuit with ACF (Anisotropic Conductive Film).

When the topmost metal layer of the metallic post 68 is solder, tin-leadalloy, tin-silver alloy, tin-silver-copper alloy or lead-free solder,and the distance from the top end of the metallic post 68 to the topsurface of the second polymer layer 70 may range from 50 to 100 microns,a heating process can be performed to reflow the topmost solder layer ofthe metallic post 68 to form solder balls after polishing and etchingthe second polymer layer 70. As shown in FIG. 19 e, thereafter, thesemiconductor substrate 30 may be similarly diced into multiplesemiconductor units. Next, the solder balls on the semiconductor unitare electrically connected to an external substrate, and then an eighthpolymer layer 148 is filled into the gap between the semiconductor unitand the external substrate and covers every solder balls.

Refer to FIG. 19 f. When the topmost metal layer of the material of themetallic post 68 is gold, copper, silver, palladium, platinum, rhodium,ruthenium, or rhenium, and the distance from the top end of the metallicpost 68 to the top surface of the second polymer layer 70 ranges from 1to 10 microns, the revealed metallic post 68 may function as a contactpad. The contact pads can be connected to an external circuit with wiresformed by a wire bonding process.

Refer to FIG. 19 g. When the material of the metallic post 68 is gold,copper, silver, palladium, platinum, rhodium, ruthenium, or rhenium, andthe distance from the top end of the metallic post 68 to the top surfaceof the second polymer layer 70 may range from 5000 angstroms to 10microns, the revealed metallic post 68 may function as a contact pad. Asixth adhesion/barrier layer 150, such as titanium, titanium-tungstenalloy, chromium, tantalum, or tantalum nitride, having a thickness ofbetween 1000 and 7500 angstroms is formed on the second polymer layer 70and on the revealed surface of the metallic posts 68. A seed layer (notshown), such as copper or gold, having a thickness of between 500 and3000 angstroms is formed on the sixth adhesion/barrier layer 150. Asshown in FIG. 19 h, a seventh patterned photoresist layer 152 is formedon the seed layer on the sixth adhesion/barrier layer 150, and openingsin the seventh patterned photoresist layer 152 reveal the seed layer onthe sixth adhesion/barrier layer 150. As shown in FIG. 19 i, an eighthmetallic layer 154 is electroplated on the seed layer exposed by theopenings in the seventh patterned photoresist layer 152. The eighthmetallic layer 154 may be formed by electroplating a single layer ofgold, copper, silver, nickel, platinum, palladium, ruthenium, rhodium,or rhenium, having a thickness of between 1 and 30 microns.Alternatively, the eighth metallic layer 154 may be formed byelectroplating a copper layer having a thickness of between 1 and 30microns, next electroplating a nickel layer having a thickness ofbetween 1 and 10 microns on the copper layer, and next electroplating agold layer having a thickness of between 1 and 10 microns on the nickellayer. Preferably, the bottommost metal layer of the fourth metalliclayer 114 has a same material as the seed layer. As shown in FIG. 19 j,the seventh patterned photoresist layer 152 is removed, and then theseed layer and the sixth adhesion/barrier layer 150 not under the eighthmetallic layer 154 are removed The eighth metallic layer 154interconnects two metallic posts 68 and functions as an interconnection.As shown in FIG. 19 k, a protection layer 156 is formed to cover thesecond polymer layer 70 and the eighth metallic layer 154 lest theeighth metallic layer 154 be damaged. The material of the protectionlayer 156 may be an organic or inorganic material or may bethermoplastic, thermosetting plastic, polyimide, BCB(Benzo-Cyclo-Butene), polyurethane, epoxy, parylene-based polymer,solder-mask material, elastic material, porous dielectric material,silicon oxide, compounds of silicon and oxygen, silicate and phosphateglass, silicon nitride, or silicon oxy-nitride.

Besides, a coil structure, a capacitor structure, a resistor structure,etc. may be connected to the pad formed by polishing and etching thesecond polymer layer 70 according to the above mentioned process in theembodiment, wherein the distance from the top end of the metallic post68 to the top surface of the second polymer layer 70 may range from 5000angstroms to 10 microns.

Embodiment 7

The structure of this embodiment is similar to that shown in FIG. 8 c,but the methods thereof are different for forming the metallic post 68and the second polymer layer 70. As shown in FIG. 20 a, afterelectroplating the first RDL 60, the photoresist layer 54 is removed andthe seed layer and the adhesion/barrier layer not under the first RDL 60are sequentially removed following FIG. 6 a. Thereafter, a ninthpatterned polymer layer 158 is formed on the first RDL 60 and on thepolymer layer 46, and the openings in the ninth patterned polymer layer158 are 20˜200 microns deep and expose the first RDL 60.

The material of the ninth patterned polymer layer 158 is thermoplastic,thermosetting plastic, polyimide, BCB (Benzo-Cyclo-Butene),polyurethane, epoxy, parylene-based polymer, solder-mask material,elastic material, or porous dielectric material. The ninth patternedpolymer layer 158 is fabricated via heat-pressing a patterned dry filmonto the semiconductor substrate 30, or via heat-pressing aphotosensitive dry film onto the semiconductor substrate 30 andpatterning the photosensitive dry film with a photolithographic method,or via heat-pressing a non-photosensitive dry film onto thesemiconductor substrate 30 and patterning the non-photosensitive dryfilm with a photolithographic method plus an etching method, or viascreen-printing the ninth polymer layer 158 where multiple openings aresimultaneously formed in the ninth polymer layer 156, or viaspin-coating a photosensitive film onto the semiconductor substrate 30and patterning the photosensitive film with a photolithographic method,or via spin-coating a non-photosensitive film onto the semiconductorsubstrate 30 and patterning the non-photosensitive film with aphotolithographic method plus an etching method.

As shown in FIG. 20 b, a seventh adhesion/barrier layer 160, such astitanium, titanium-tungsten alloy, chromium, tantalum, or tantalumnitride, having a thickness of between 400 and 7000 Å is sputtered onthe ninth patterned polymer layer 158, on the first RDL 60 exposed bythe openings in the ninth patterned polymer layer 158, and on the sidewalls of the openings in the ninth patterned polymer layer 158. A seedlayer (not shown), such as copper or gold, having a thickness of between500 and 7500 angstroms is sputtered on the seventh adhesion/barrierlayer 160. As shown in FIG. 20 c, a ninth metallic layer 162 iselectroplated with a Damascene method on the seed layer on the seventhadhesion/barrier layer 160 until the ninth metallic layer 162 fills allremaining space in the openings in the ninth patterned polymer layer158. The ninth metallic layer 162 may be formed by electroplating acopper layer having a thickness of between 1 and 30 microns on the seedlayer, preferably made of copper, exposed by the openings in the ninthpatterned polymer layer 158. Alternatively, the ninth metallic layer 162may be formed by electroplating a gold layer having a thickness ofbetween 1 and 30 microns on the seed layer, preferably made of gold,exposed by the openings in the ninth patterned polymer layer 158.

As shown in FIG. 20 d, the ninth metallic layer 162, the seed layer andthe seventh adhesion/barrier layer 160 outside the openings in the ninthpatterned polymer layer 158 are removed with a chemical mechanicalpolishing (CMP) method or a mechanical grinding method. Thereby, themetallic posts 68 are formed. The ratio of the maximum horizontaldimension Hw of the metallic post 68 to the height Ht of the metallicpost 68 is less than 4 or even less than 1. The maximum horizontaldimension of the metallic post 68 is 3˜50 microns; the spacing betweenthe centers of the neighboring metallic posts 68 is 10˜250 microns.

The metallic post 68 formed with the Damascene method has a similarprofile to that disclosed in FIG. 8 c; therefore, the method tofabricate other elements above the ninth patterned polymer layer 158 andthe metallic posts 68 is the same as those formed in the abovementionedembodiments.

FIG. 21 a through FIG. 21 d disclose the bumps, contact pads, solderballs and RDL's formed on the ninth patterned polymer layer 158 and themetallic posts 68. Herein, only the completed structures are disclosed;the fabrication methods thereof have been stated in the abovementionedembodiments and will not be described repeatedly.

FIG. 22 to FIG. 25 disclose the interconnection metal trace, coil,capacitor element, and resistor element formed on the ninth patternedpolymer layer 158 and on the metallic posts 68. Herein, only thecompleted structures are disclosed; the fabrication methods thereof havebeen stated in the abovementioned embodiments and will not be describedrepeatedly.

The present invention can apply to release stress and reduce the spacingbetween metal posts to be less than 250 microns. Further, the presentinvention can increase the pin count to be more than 400. Furthermore,the present invention can greatly reduce the impedance and loading ofthe metallic connection circuit of low-power IC elements and theneffectively promote the performance of IC elements.

Those embodiments described above are to clarify the present inventionto enable the persons skilled in the art to understand, make and use thepresent invention. However, it is not intended to limit the scope of thescope of the present invention, and any equivalent modification andvariation according to the spirit of the present invention is to be alsoincluded within the scope of the claims of the present invention statedbelow.

1. A method for fabricating a circuit component, comprising: providing asemiconductor wafer, a first metal layer over said semiconductor wafer,and a first polymer layer over said first metal layer and over saidsemiconductor wafer; polishing said first polymer layer and uncovering asurface of said first metal layer; after said polishing said firstpolymer layer, forming a second metal layer over said first polymerlayer and on said surface; after said forming said second metal layer,forming a photoresist layer on said second metal layer, wherein anopening in said photoresist layer exposes a region of said second metallayer; after said forming said photoresist layer, forming a third metallayer over said region; after said forming said third metal layer,removing said photoresist layer; and after said removing saidphotoresist layer, removing said second metal layer not under said thirdmetal layer.
 2. The method of claim 1, wherein said first metal layercomprises a first metal post and a second metal post, wherein a pitchbetween said first metal post and said second metal post is between 10micrometers and 250 micrometers.
 3. The method of claim 1, wherein saidfirst metal layer comprises a gold layer with a thickness between 20 and300 micrometers over said semiconductor wafer.
 4. The method of claim 1,wherein said first metal layer comprises a copper layer with a thicknessbetween 20 and 300 micrometers over said semiconductor wafer.
 5. Themethod of claim 1, wherein said first metal layer is formed by a processcomprising an electroplating process.
 6. The method of claim 1, whereinsaid forming said second metal layer comprises a sputtering process. 7.The method of claim 1, wherein said forming said third metal layercomprises electroplating a gold layer with a thickness between 2 and 50micrometers over said region.
 8. The method of claim 1, wherein saidforming said third metal layer comprises electroplating a copper layerwith a thickness between 2 and 30 micrometers over said region.
 9. Themethod of claim 1, wherein said forming said third metal layer comprisesforming a tin-containing layer with a thickness between 20 and 150micrometers over said region.
 10. The method of claim 1, wherein saidforming said second metal layer comprises forming a titanium-containinglayer over said first polymer layer and on said surface.
 11. The methodof claim 1, after said polishing said first polymer layer, furthercomprising forming a second polymer layer over said first polymer layer,followed by said forming said second metal layer further on said secondpolymer layer.
 12. The method of claim 1, wherein said opening has acoil-shaped space.
 13. The method of claim 1, after said removing saidsecond metal layer not under said third metal layer, further comprisingforming a wire connected to said third metal layer by a wire bondingprocess.
 14. A method for fabricating a circuit component, comprising:providing a semiconductor wafer, a first metal post over saidsemiconductor wafer, wherein said first metal post has a height between20 micrometers and 300 micrometers, and a second metal post over saidsemiconductor wafer, wherein a pitch between said first metal post andsaid second metal post is between 10 micrometers and 250 micrometers;forming a first insulating layer over said semiconductor wafer and onsaid first and second metal posts; after said forming said firstinsulating layer, removing said first insulating layer and uncovering afirst surface of said first metal post and a second surface of saidsecond metal post using a process comprising a polishing process; aftersaid removing said first insulating layer, forming a first metal layerover said first insulating layer and on said first and second surfaces;after said forming said first metal layer, forming a photoresist layeron said first metal layer, wherein an opening in said photoresist layerexposes a region of said first metal layer; after said forming saidphotoresist layer, forming a second metal layer over said region; aftersaid forming said second metal layer, removing said photoresist layer;and after said removing said photoresist layer, removing said firstmetal layer not under said second metal layer.
 15. The method of claim14, after said removing said first metal layer not under said secondmetal layer, further comprising forming a wire connected to said secondmetal layer by a wire bonding process.
 16. The method of claim 14,wherein said first metal post comprises a copper layer with a thicknessbetween 20 and 300 micrometers over said semiconductor wafer.
 17. Themethod of claim 14, wherein said first metal post comprises a gold layerwith a thickness between 20 and 300 micrometers over said semiconductorwafer.
 18. The method of claim 14, wherein said first metal post isformed by a process comprising an electroplating process.
 19. The methodof claim 14, wherein said forming said second metal layer compriseselectroplating a gold layer with a thickness between 2 and 50micrometers over said region.
 20. The method of claim 14, wherein saidforming said second metal layer comprises electroplating a copper layerwith a thickness between 2 and 30 micrometers over said region.
 21. Themethod of claim 14, wherein said forming said second metal layercomprises electroplating a tin-containing layer with a thickness between20 and 150 micrometers over said region.
 22. The method of claim 14,wherein said forming said first metal layer comprises sputtering atitanium-containing layer over said first insulating layer and on saidfirst and second surfaces.
 23. The method of claim 14, after saidremoving said first insulating layer, further comprising forming asecond insulating layer on said first insulating layer, followed by saidforming said first metal layer further on said second insulating layer.24. The method of claim 14, wherein said first insulating layercomprises a polymer.
 25. A method for fabricating a circuit component,comprising: forming a first opening in a device, wherein said firstopening has a depth between 20 and 200 micrometers; after said formingsaid first opening, forming a first metal layer on a surface of saiddevice, in said first opening and at a sidewall of said first opening;after said forming said first metal layer, electroplating a second metallayer over said first metal layer, over said surface and in said firstopening; after said electroplating said second metal layer, removingsaid first and second metal layers outside said first opening and oversaid surface using a process comprising a polishing process; after saidremoving said first and second metal layers, forming a third metal layerover said surface and on said second metal layer at a top of said firstopening; after said forming said third metal layer, forming aphotoresist layer on said third metal layer, wherein a second opening insaid photoresist layer exposes a region of said third metal layer; aftersaid forming said photoresist layer, forming a fourth metal layer oversaid region; after said forming said fourth metal layer, removing saidphotoresist layer; and after said removing said photoresist layer,removing said third metal layer not under said fourth metal layer. 26.The method of claim 25, wherein said forming said first metal layercomprises a sputtering process.
 27. The method of claim 25, wherein saidelectroplating said second metal layer comprises electroplating a copperlayer over said first metal layer, over said surface and in said firstopening.
 28. The method of claim 25, wherein said forming said thirdmetal layer comprises sputtering a titanium-containing layer over saidsurface and on said second metal layer at said top of said firstopening.
 29. The method of claim 25, wherein said forming said fourthmetal layer comprises electroplating a gold layer with a thicknessbetween 2 and 50 micrometers over said region.
 30. The method of claim25, wherein said forming said fourth metal layer compriseselectroplating a copper layer with a thickness between 1 and 100micrometers over said region.
 31. The method of claim 25, wherein saidforming said fourth metal layer comprises electroplating atin-containing layer with a thickness between 20 and 150 micrometersover said region.